Heating, bending and cooling system for glass

ABSTRACT

The present invention provides a heating, bending and cooling system for glass, which comprises a horizontally-standing bending mold located in an oven. The mold includes two or more hollow supporting elements which are separated from each other. At least one of the ends of each of the supporting elements extends out of the chamber of the oven through a plate. The upper part of the chamber of the oven includes at least one hollow upper element which acts as a heating and cooling element which can be lowered to a position above the supporting elements. The supporting elements not only support a glass sheet placed thereon but also bend the glass sheet when it is heated. The supporting elements also act as heating elements and cooling elements. In addition, the supporting elements are oscillated to keep the surfaces of the supporting elements touching the glass in constant motion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system for heating, bending andcooling of glass.

2. Prior Art

A mold system used in the bending of glass has been described in U.S.Pat. No. 2,526,359. In this mold system, the bending mold is convexupwards and when the glass sheet is lowered over the mold, the glasssheet is supported by central parts of the mold. The mold includes twoside template plates which position the pipes forming the mold at thedesired bending curvature. The pipes are separated from each other at aconstant distance by vertical members and the pipes can only move invertical direction. The "pipe" mold is supported in its center by abrace, which can give support only in a vertical direction. To produce adesired shape of glass, the template plates and the middle located braceare replaced with templates and a brace, which are formed to give adesired shape of glass.

In U.S. Pat. No. 2,223,124 a method is described in which a horizontalglass plate is placed on a roll device, which in the beginning hashorizontal rolls which are separately supported and are spaced apartfrom each other. While the glass is heated, these rolls areincrementally lowered and while these rolls are lowered, they give shapeto the glass. By varying guidance of the rolls, one can producedifferent kind of shapes.

The aforementioned glass bending methods have many problems. In bothmethods the mold needs a heavy frame construction which causes a greatdeal of difficulty, because the frame is located in the oven, which isboth heated and cooled.

In the construction shown in U.S. Pat. No. 2,256,359, the pipes have tobe unbending, they are also heavy, because they are supported in axialdirection only at their ends and in the middle they are only carried.The frame of the mold is not adjustable and the pipes used have to befull length even in case of small glass sheet bending. In a heavy molddifferent parts may warm up at different times and they may even remainat different temperatures, which causes distortions. Because the pipesare not supported in axial direction in the middle, it is particularlyeasy to get distortions in pipes.

In the construction shown in U.S. Pat. No. 2,223,124 it is troublesometo guide lowering of the roll devices, which is a very difficultoperation and which must be done inside the oven. Because ofconstruction of the roll device it is also impossible to make the moldsmaller in any simple way when it is used with smaller glass sizes. Inaddition to this there is a special difficulty in using rolls, becausethis is done in a hot environment (about 600 ° C.) and shape of the rolldevices is changing all the time.

The heating, bending and cooling system according to present inventionprovides a significant improvement over the prior art molds.

SUMMARY OF THE INVENTION

The present invention provides a heating, bending and cooling system forglass, which comprises a horizontally-standing bending mold located inan oven. The mold includes two or more hollow supporting elements whichare separated from each other. At least one of the ends of each of thesupporting elements extends out of the chamber of the oven through aplate. The upper part of the chamber of the oven includes at least onehollow upper element which acts as a heating and cooling element whichcan be lowered to a position above the supporting elements. Thesupporting elements not only support a glass sheet placed thereon butalso bend the glass sheet when it is heated. The supporting elementsalso act as heating elements and cooling elements. In addition, thesupporting elements are oscillated to keep the surfaces of thesupporting element touching the glass in constant motion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a heating, bending and cooling systemfor glass according to the invention with a portion of the system brokenaway to show interior detail.

FIG. 2 shows a supporting element according to the invention.

FIG. 3 shows an upper element according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1 an oven 1 located bending mold system, consists of atleast two template plates 3 which are supported in vertical position bysupporting members 4. Upper edges of template plates 3 are constructedto support supporting elements or pipes 5 in an axial direction and tocarry them. Pipes 5 act as bending mold for glass, and the form of themold is determined by template plates 3. Ends of pipes 5 are extendthrough plates 17 out of the oven. Outside the oven, pneumatic air canbe led through flexible pipes 7 to pipes 5 and electricity from avoltage source (not shown) can be directed through copper wire 9 topipes 5. Pneumatic pipe 7 and copper wire 9 are coaxially integrated.Copper wire 9 is coated with insulating material 8. Oscillating/rotatingmovement is given to pipes 5 by a mechanism comprising a device 13 whichmoves back and forth a rod 12, causing a lever 11 of each pipe 5 to movethe pipe 5 back and forth. Adjacent levers 11 are connected by rods 10.The glass sheet 6 to be bent is laid over pipes 5. Pipes 5 can act asheating device of glass with electricity which is led to pipes 5. Whileglass 6 is heated and molded by pipes 5, the pipes 5 can be given anoscillating movement to prevent the formation of contact marks in thesurface of glass 6. After glass 6 is molded, pressurized air is blownout of holes 26 in pipes 5 and in this way glass 6 is cooled. The numberof pipes 5 used can be variable. Glass sheet (6) can also beelectrically heated and pneumatically cooled by one or more upperelement 14. Upper element 14 can be lowered near to glass sheet 6 to adistance of about 5-20 cm and element 14 can be moved during itsfunctioning.

In FIG. 2 there is shown one of a group of the pipes 5 which forms abending mold. The pipe 5 consists of an inner pipe 25 which at one endis mounted in end member 24 . Because of thermal expansion, inner pipe25 is separated by sliding ceramic spacers 22 from outer pipe 5.Movement of spacers 22 on inner pipe 25 is prevented stops 23. The wallsof inner pipe 25 are thin and inner pipe 25 becomes hot when electricitygoes through it, so pipe 5 can be used as heating element. The walls ofinner pipe 19 are thick and it is a good conductor of electricity, so itdoesn't get warm when electricity travels through it to inner pipe 25.Electricity is directed to pipe 19 through copper wire 9 and quickjoining part 16. From the end member 24 electricity travels throughouter pipe 5 to the frame of mold 20. Pressurized air is directed topipes 19 and 25 through pipe 7 and quick joining part 16. End member 21prevents leaks of pressurized air. Highly pressurized air flows throughinner pipes and out through holes 27 into the space between pipes 5 and7 where the pressure of the air is stabilized and the air flows smoothlythrough holes to glass sheet 6. Lever 11 is joined to an end of pipe 5with band 18. In the pipe 5 there is a guidance hole (not shown) thathelps to adjust lever to the correct position relative to holes 26.Lever 11 moves pipe 25 back and forth. In the pipe 5 holes 26 are in twolines that are arranged so that neither of the two hole lines can beturned so much that it would face a surface of glass sheet 6 while thepipe 5 is oscillated.

In FIG. 3 there is shown an upper element 14, which receives electricitythrough copper wires 9 and pipe 29 which are good conductors ofelectricity. However, pipe section 14 gets warm when electricity passesthrough it and acts as heater. The composition of the pipe formed bypipe 29 and upper element 14 changes at a point 30 from being moreconductive to being less conductive. Pressurized air is blown out ofholes to cool glass sheet 6. Fixtures 28 can be used to fix upperelement 14 to fix upper element 14 to a device which moves upper element14 in a vertical direction.

While only some embodiments of the present invention have been describedin detail herein, various modifications and changes may be appliedwithout departing from the scope of the invention.

I claim:
 1. A heating, bending and cooling system for glasscomprising:an oven having a chamber therein including at least onevertical plate; hollow supporting elements extending in a horizontaldirection within said chamber and having at least one end which extendsout of said chamber through said at least one vertical plate, saidhollow supporting elements being arranged to bend a sheet of a glassplaced thereon when the glass is heated, each of said hollow supportingelements including a first heating means for heating glass locatedthereon and a cooling means for cooling glass located thereon; at leastone plate for supporting said hollow supporting elements in said bendingarrangement; means for oscillating said hollow supporting elements in adirection perpendicular to the direction in which said hollow supportingelements extend; and an upper element located above said hollowsupporting elements for heating the sheet of glass located on saidhollow supporting elements, and means for lowering said upper elementover the sheet of glass.
 2. A heating, bending and cooling system forglass according to claim 1, wherein said first heating means comprisesan inner pipe located within each said hollow supporting element, saidinner pipe being electrically heated.
 3. A heating, bending and coolingsystem for glass according to claim 1, wherein said upper elementcomprises a bent pipe which is electrically heated.
 4. A heating,bending and cooling system for glass according to claim 1, wherein saidhollow supporting elements include holes extending therethrough and saidcooling means comprises means for supplying pressurized air through saidhollow supporting elements and out of said hollow supporting elementsthrough said holes.
 5. A heating, bending and cooling system for glassaccording to claim 1, wherein said upper element is hollow, includessecond holes extending therethrough and includes second cooling meanscomprising means for supplying pressurized air through said hollowsupporting elements and out of said hollow upper element through saidsecond holes.